1. Wed 5/25 Lesson 11 – 7 Learning Objective: To find standard deviation & variance Hw: Pg. 722 #6 – 9, 13, 21

2. Algebra II

3.  To find standard deviation  To find variance

4. Low standard deviation – data points are close to the mean High standard deviation – data points are spread out over a wider range of values Same units as the data set (Main difference from a variance)

5. Low variance – data points are close to the mean high variance– data points are spread out over a wider range of values Variance of zero = all data values are identical

6. AverageAdd all #s and divide by amount of #s How far each number is from the mean Subtract each number from the mean VarianceAverage of the squares of the deviations Standard Deviation How much data deviates from the mean Square root of the variance

8. 1.146, 189, 246, 178, 203 = 192.4 x c 146-46.4 2152.96 189-3.4 11.56 24653.6 2872.96 178-14.4 207.36 20310.6 112.36 5357.2 (sum) Standard dev

9. 1.146, 189, 246, 178, 203 159.7225.1 127 257.8 X X X XX 2 standard deviations from the mean

10. 121314 15 171819 2021 2224 5.64.63.6 2.6 0.60.41.4 2.43.4 4.46.4 Mean: Variance: Standard Deviation: 10 12 1416 18 2022 2426 1 1 2 2 Mean 17.6 14.121.1 10.6 24.6 9 within 1 SD All/15 within 2 SD x

11. 3344457889910 1114 4.3 3.3 2.30.30.7 1.7 2.7 3.76.7 Mean: Variance: Standard Deviation: 2 4 68 10 1214 16 1 1 2 2 7.34.1 10.5 0.9 13.7 8 within 1 SD 14 within 2 SD All/15 within 3 SD 3 16.9 x